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VY 3.8..rough idle..lose of power

Peter Hills

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Hi Guys n Gals..the issue im having with my VY 2002 3.8 is it starts and runs ok.But then after giving it a rev it runs rough..rough idle like it running on 5 cylinders and not 6..lve changed fuel filter,spatk plugs n leads,ignition coils...lm running out of ideas..fuel pump maybe??(hope not)but fuel is getting thru..i put some injector cleaner in the system to try and maybe clear any blockages..but no good..starts n runs well..go for a quick test drive and its back to rough idling...and now for the past 3 nights my alarm trips and goes off.and its in doors.wtf..what next
 
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krusing

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Hmm, Sounds bit like a Vac leak,
Maybe check the Vacuum lines,
Also, maybe clean the Throttle Body, & IAC Valve, because they carbon up all the time.
Plug leads on Correctly, as I know they are a bit of a bugger sometimes,
Plugs gapped correctly ?
I read you replaced the plugs, but if the gaps are to wide, it can cause the leads to ark across to each other.
Maybe the CAS, I wouldn't count that out either,

The other option, maybe get the Car scanned, because not all errors will activate the screen to display a error,
Where it still could be in the ECU history,
Which could point you in the right direction of the error.
 
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Trevor loves holden.

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If your alarm is going off I be cheeking for a loose earth lead, flat or faulty battery, over charging or low charging Alternator.
Test coils by removing the 2 leads off one coil start car if spark jumps post to post good coil, do it on all 3 see if they pass the test, don't count out the DFI.
 

Peter Hills

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If your alarm is going off I be cheeking for a loose earth lead, flat or faulty battery, over charging or low charging Alternator.
Test coils by removing the 2 leads off one coil start car if spark jumps post to post good coil, do it on all 3 see if they pass the test, don't count out the DFI.
Hmm, Sounds bit like a Vac leak,
Maybe check the Vacuum lines,
Also, maybe clean the Throttle Body, & IAC Valve, because they carbon up all the time.
Plug leads on Correctly, as I know they are a bit of a bugger sometimes,
Plugs gapped correctly ?
I read you replaced the leads, but the gaps are to wide, it can cause the leads to short to each other.
Maybe the CAS, I wouldn't count that out either,

The other option, maybe get the Car scanned, because not all errors will activate the screen to display a error,
Where it still could be in the ECU history,
Which could point you in the right direction of the error.
Anyone out there??
Hey Guys...
Thanks for all yr tips. Yesterday l did just that..removed the throttle body and gave it a clean..and it needed it..checked vac hoses and found them loose..tighten up the coil harness..l honestly dont think the car had been serviced much before l got this 3yrs ago..l plan on replacing the fuel injectors. Put everything bck together and went for a ride ..and no rough idling..l live out country in the Waikato and my rd is 10km long. Now that l can trust driving it into town ill get the codes checked out. This isnt my primary vehicle l soend more time in my work van..but feel much better now that lve gotten this far with it.
Appreiate yr feedbck
 

Peter Hills

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But the biggest rookie mistake l made..was not disconnect the Batt before hand..because l didnt the computer didnt reg the repairs made and the car ran rough..until l disconnected the Batt and the computer reset...runs well now..but now were in 4week lock down...
 

Peter Hills

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Well rough idle carried on ..after doing all of the above...l thought stuff it...l removed all down to the inlet manifold..and there it was..all 12 bolts holding that in were loose..like a hooker at the end of a night shift..wtf...so with everything tighten down in sequence and everything back on.. plenum and throttle body clean and.new fuel injectors fitted (with everything off l may as well chang them)etc..vac hoses on tight n secure ...she runs a damn sight better and no poor ideling..persistance pays in the end...another rookie mistake..never disconnect the batt after locking up at the end of the day..in the morning..l couldnt get bck in..Damn..so l got a rag..a screw driver and a bit of No8 wire..lifted the the bonnet up a bit and shuffled the batt terminal with my No8 just enough to touch the - batt terminal...lm in...never again
 
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krusing

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Funny you mention the loose LIM bolts,
I found the same thing approx. a month ago, and got at least 1/2 a turn out of them to nip them up, and that confirmed the carrot milk shake in the radiator I had.
But mine never idled rough at all, all the time they have been loose.
So I then decided to get on and do the LIM gaskets,
However I never though it would cause it to idle rough, but yet again, anything is possible.
Maybe since you found the bolts were loose,
the gaskets could be either damaged in some way, or not sealing correctly, probably best to replace them if you can afford it, and the time, the LIM gasket kit are not that expensive, and it could even increase your fuel economy,
As I know it did with mine.
But well done in your result/find.
 
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Peter Hills

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And after all the wrk done ...it was a faulty Alternator...wtf..not giving me enough batt charge to run everything...fuel inject..etc=rough idle....lm getting a code scanner next time..but was a good exercise l got to know the car bit more..haha...
 
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